Fragmented red cells reference range (Sysmex XN(®) automated blood cell counter).

ABSTRACT

Fragmented red cells (FRCs) is a new parameter automatedly determined by recent blood cell counters. Their count might be of interest because FRCs are supposed to reflect schistocytes counts measured on a stained peripheral blood smear observed under the microscope. But FRCs depend from the technical procedure used to detect them and thus reference ranges are device-dependent. The XN-9000(®) is one of the last model from Sysmex series. We aimed to establish reference range for FRCs, from 2389 controls. The mean ± SD was 0.32% ± 0.81, the median 0.02% (95% confidence interval ot the mean 0.29-0.35%). We observed that the percentage of red blood cells with less than 17 pg of hemoglobin content (Hypo-He) was correlated to FRC increase, Hypo-He increase resulting in spurious FRCs majoration. FRCs reference range should be useful for 1) laboratory staff in order to select which blood smears to check optically; 2) Sysmex company to set-up more optimal rules proposed with the counter (automated making of blood smear).